Carburetor attachment



April 19, 1938. w, STADLMAN 2,114,548

CARBURETOR ATTACHMENT Filed Feb. 25, 1935 ATTORNEY.

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Patented Apr. 19, 1938 4 Claims.

This invention relates to carburetion and more -particularly to forminga combustible mixture for an internal combustion engine; and has for itsobject to properly proportion and mix the air and fuel under varyingconditions of load and speed. i

More particularly it is an object of the invention to increase the jetaction at the fuel nozzle 01' the carburetor which forms the combustiblemixture, so as to generate a dry gas, and prefer'ably to increase thejet action as the throttle is opened.

It is a further object of the invention to increase the pressure of theair which at the Venturl tube of the carburetor entrains and then'ntomizes and vaporizes the fuel, and to preferably increase the airpressure as the throttle is opened; v

i urther objects of the invention will be readily understood from thefollowing description of the accompanying drawing, in which:

Fig. l is a side elevation of the invention, with the throttle in idlingposition.

Fig. 2 is a transverse section on the'line ti oi l, with the throttle infull open position.

Fig. 3 is an axial section on the line ii-t of The invention isapplicable to a usual carburetor for an internal combustion engine, thecar huretor including fuel nozzle i supplied from a heat chamber 2 andhaving an air intake from whence the air flows through a Venturi tube iwhich surrounds the fuel nozzle. As shown at l the fuel nozzlepreferably opens into the i'entm'i tube in the direction of flow throughthe Venturi tube, and the discharge orifice of the fuel nozzle ispreferably at or adjacent the marinlum cross-sectional restriction ofthe Venturi tube. A combustible mixture is thus formed in usual mannerand is drawn through the intake manifold b and past the throttle valvet'into the engine cylinders, the exhaust manifold for the enginecylinders being shown at l.

The present invention preferably provides additional flow into the.intake manifold it as the throttle it is opened; and this additionalflow is under considerable pressure and creates turbulence in theintake-manifold as well as reducin the vacuum therein, and is preferablyalso adapted to raise the temperature or the combustible mixture and tosupply exhaust gases thereto.

For this purpose a housing it) may be mounted in the intake manifold b,preferably between its usual coupling flanges iii-i2, the housing beingheld in place by the usual flange bolts it. The

housing has a bore M in alinement with and slightly larger than the boreof the intake manifold, and a sleeve I5 is mounted in this bore andisheld in place between the flanges ll-I2 as shown at Fig. 3. The sleevel5 has a series of circumferentially spaced ports I6 opening into thebore of the intake manifold, and the housing it! forms an annularchamber l'l surrounding and communicating with the ports, with apassageway [8 leading to the annular chamber.

At its outer end the passageway l8 communicates with a valve chamber itwhich is formed in housing it, the valve chamber being shown ascylindrical and adapted to receive a rotary valve 2%, and the valvechamber has an intake nipple 2i circumferentially spaced from thepassageway it. The valve ill when turned to the position shown at Fig. icloses the intake nipple 2i, but iscut away at one side as shown at 22so that when turned in the direction of arrow A to the position shown atFigs. 2 and 3, it opens the nile ii to the passageway in.

The valve it may be rotated by a lever 23 which is linked at it to thelever 25 for the throttle valve t, so that when throttle rod ill isshifted in the direction to open the throttle t, the valve it is alsoopened as shown at Fig. 3,- and when the throttle is closed to idlingposition the valve 2b is also closed as shown at Fig. l.

Exhaust gases from theengine are preferably supplied to the intakenipple 2 i, and for this purpose a conduit til communicates with theexhaust manifold l and leads to the intake nipple.

The invention provides means for increasing the jet action at fuelnozzle i, preferably as the throttle lt is opened, and for this purposeadditional flow under pressure is supplied to the mouth of the Venturitube 45 for entraining and then atomizing and vaporizing fuel, and thisadditional flow is preferably adapted to raise the temperature of thefuel which is drawn into the Venturi tube and to supply exhaustgasestheretov For this purpose a conduit '35 has a discharge end ttsurrounding the fuel nozzle i in the mouth of Venturi tube t, with thedischarge end {it preferably at or adjacent the discharge-orifice of,the fuel nozzle as shown at Fig. 1, whereby the discharge end tilt ispreferably at or adjacent the maximum cross-sectional restriction of theVenturi tube. The conduit 35 is preferably supplied with exhaust gasesfrom the manifold i, the supply being preferably cor'itrolled inaccordance with the position of the throttle 8. As an instance of thisarrangement the valve chamber it may have an outlet nipple 3icommunicating with the conduit 35, and the cut away portion of valve 20may be so arranged that when the valve is turned for opening the intakenipple 2! to the passageway l8, it also opens the intake nipple to theoutlet nipple 31 as shown at Fig. 3. 4

In operation, when the throttle 6 is closed to idling position the valve20 is also c1osed,.so that the carburetor supplies a combustible mixturein usual manner, with suction past the nearly completely closed throttledrawing in air through intake 3 so that the air entrains and thenatomizes and vaporizes fuel at the pointvof maximum cross-sectionalrestriction of the Venturi tube 4, but as the throttle 6 is opened thevalve 20 is correspondingly opened, whereby exhaust gases are suppliedvia conduit 35 for discharge into the stream of air being drawn inthrough the air intake 3, with" said discharge adjacent the orifice ofthe fuel nozzle and adjacent the point of maximum cross-sectionalrestriction of the Venturi tube 4. The exhaust gases thus function withmaximum efflciency to increase the jet action of the stream of air fordrawing fuel into the Venturi tube, thereby maintaining the proper fuelratio for different speeds and loads and heating the fuel for completevaporization, and'by forming a part of the combustible mixture insuringfuel economy and tending to maintain the same proportion of exhaustgases in the fuel charge at different positions of the throttle.

At the same time a part of the exhaust gases, controlled by the positionof valve 20 which is in turn controlledby the position of the throttle,

are preferably discharged through ports l8 into the combustible mixturein the intake manifold 5, the additional flow being introduced at apoint between the throttle valve 6 and the cylinders of the engine asshown at Fig. 1. These exhaust gases being under pressure reduce thevacuum in the intake manifold as the engine is accelerated, therebyassisting in maintaining the proper fuel ratio for different speeds .andloads, and also create turbulence in the intake manifold, insuring athorough mixture of the air and fuel.

The invention thus provides an efllcient combustible mixture with theair and fuel properly proportioned for varying conditions of speed andload, and with the exhaust gases which are supplied to the Venturi tubeat its maximum crosssectional restriction and at the discharge orificeof the fuel nozzle, thereby functioning with maximum efiiciency toincrease the jet action and supply heat for vaporizing the fuel, thussupercharging the combustible mixture and increasing the volumetricefilciency of the engine, making it, possible to burn low grade fueloils in a low compression, high speed engine,

' Lclaim: v

,1. In a carburetor adapted to form a combustible mixture for aninternal combustion engine, a Venturi tube having an air inlet at oneend and at its opposite end forming a passageway supplying combustiblemixture to the engine,

the throttle.

2. In a carburetor adapted to form a combustible mixture for an internalcombustion engine, a Venturi tube having an air inlet at one end and atits opposite end forming a passageway supplying combustible mixture tothe engine,

a fuel jet having a discharge orifice opening into the Venturl tube inthe direction of flow therethrough and at a point justbefore'maximumu'estriction of the Venturi tube, a conduit for fluidwhich will mix with and form a component of the combustible mixture,said conduit having a discharge end surrounding the fuel jet and openinginto the Venturi tube adjacent the discharge orifice of the jet. a valvecontrolling flow of fluid through the conduit, a throttle controllingflow of combustible mixture to the engine, and means for opening andclosing the valve in accordance with the position of the throttle.

3. In a carburetor adapted to form a combustible mixture for an internalcombustion engine, a Venturi tube having an air inlet at one end and atits opposite end forming a passage-;- way supplying combustible mixtureto the engine, a fuel jet having a discharge orifice opening into theVenturi tube adjacent maximum restriction of the Venturi tube, a conduitfor exhaust gases of the internal combustion engine having a dischargeend opening into the Venturi tube just before maximum restriction ofsaid tube, a valve controlling flow of exhaust gases through'saidconduit, a throttle controlling flow of combustible mixture to theengine, and means for opening and closing" the valve in accordance withthe position of the throttle.

4. In a carburetor adapted to 'form a combustible mixture for aninternal combustion engine, a Venturi tube having an air inlet at oneend-and at its opposite end forming a passageway supplying combustiblemixture to the engine,

a fuel jet having a discharge orifice-opening into the Venturi tubeadjacent maximum restriction

